package com.test.str;

public class StringBuilderDemo {

    public static void main(String[] args) {
        Integer userId = 1;
        String s = new StringBuilder(userId.toString()).append("_FyManagementUserMenu").toString();
        System.out.println(s);

        String ss = "[{'userId': 1},{'userName': 'laoda1'}]";

        System.out.println(isJson(ss));
    }


    public static boolean isJson(String str) {
        System.out.println(str.startsWith("{"));
        System.out.println(str.startsWith("["));
        if (!str.startsWith("{") && !str.startsWith("[")) {
            return false;
        }
        return true;
    }
}
